Multi-condition responsive fluidic pulse generator for fluidic fuel injection system

ABSTRACT

A fluidic pulse generator is disclosed which is capable of responding to a plurality of inputs having both digital and analog characteristics and of providing an output signal having a pulse duration which is a function of the various input parameters. Such a device is of utility when used as the main fuel injection pulse computing device in a fluidic fuel injection system. The circuitry is comprised of a plurality of fluidic gating devices and the variable time determinative means which includes a chargeable volume and a variable restriction illustrated in the form of a vortex fluidic device.

United States Patent [191 Taplin Sept. 25,1973

1 1 MULTI-CONDITION RESPONSIVE FLUIDIC PULSE GENERATOR FOR FLUIDIC FUEL INJECTION SYSTEM [75] Inventor: Lael B. Taplin, Livonia, Mich.

[73] Assignee: The Bendix Corporation, Southfield,

Mich.

221 Filed: Mar. 30, 1972 [21] Appl. No.: 239,739

[52] U.S. Cl 137/820, 137/810, 123/119 R [51] Int. Cl. FlSc 1/12 [58] Field of Search 137/8l.5, 810, 820; 123/119 R, 103 R; 60/3928 [56} References Cited UNITED STATES PATENTS 3,616,782 11/1971 Matsui et a1. l37/81.5 X

3,687,121 8/1972 Tuzson 123/103 R 3,690,306 9/1972 Matsui et a1. 123/119 R FOREIGN PATENTS OR APPLICATIONS 1,227,883 4/ 1971 Great Britain Primary ExaminerWilliam R. Cline Attorney-John S. Bell and Bruce A. Yungman 5 7 ABSTRACT A fluidic pulse generator is disclosed which is capable of responding to a plurality of inputs having both digital and analog characteristics and of providing an output signal having a pulse duration which is a function of the various input parameters. Such a device is of utility when used as the main fuel injection pulse computing device in a fluidic fuel injection system. The circuitry is comprised of a plurality of fluidic gating devices and the variable time determinative means which includes a chargeable volume and a variable restriction illustrated in the form of a vortex fluidic device.

; 12 Claims, 3 Drawing Figures its OUTPUT FROM MODULE MULTI-CONDITION RESPONSIV E FLUIDIC PULSE GENERATOR FOR FLUIDIC FUEL INJECTION SYSTEM CROSS REFERENCE TO RELATED APPLICATION The present application is related to applicants copending commonly assigned application Ser. No. 239,678 entitled Fluidic Fuel Injection System Having Transient Engine Condition Responsive Means To Controllably Effect The Quantity of Fuel Injected" filed on the same data as the instant application.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of fluidically controlled fuel systems for internal combustion engines and more particularly to that portion of the above-noted field which is concerned with the provision of fuel in discreet intermittent pulses commonly referred to as fuel injection. The present invention is more particularly related to that portion of the above noted field which is concerned with the generation of a basic pulse whose duration is representative of the duration of fuel delivery required to mmet the then current operating requirements of the engine.

2. Description of the Prior Art The prior art, as it relates to the above-noted field, teaches that a monostable fluidic element which may be driven into its nonstable condition for a variably controlled period of time (typically by a feed back loop incorporating a variable capacitive type element such as a chargeable volume) may be used to generate the desired injectioncontrolling pulse. Typically, the feed back loop of such a device is communicated to the intake manifold to give a signal indicative of the air consumption by the engine and a control signal is applied to a control port of the device in synchronization with the operating cycle of the engine to provide the neces sary timing input. The practical use of such devices has illustrated however that further parameters are required to provide the accuracy demanded by the present emission control laws. Furthermore, the timing event does not readily lend itself to different timing requirements which may be encountered in the engine operating cycle. It is therefore an object of the present invention to provide a multicondition responsive fluidic pulse generator which is capable of forming an output pulse having a controlled time duration which is controlled in response to a plurality of inputs which may include digital as well as analog inputs. It is a further object of the present invention to provide such a pulse generator which responds to trigger signals with a timing relationship between the trigger signal and the initiation of the output pulse which may be controllably varied.

A further difficulty which has been encountered in the prior art devices is the difficulty with which the variable volume capacitive like element may be charged and discharged. It is therefore a still further object of the present invention to provide an improved pulse generator in which the time duration controlling element is more readily charged and/or discharged.

SUMMARY OF THE PRESENT INVENTION The present invention comprises a plurality of fluidic elements including bistable and monostable gating elements and a vortex device. The bistable devices are connected in parallel with the monostable device being in series with one of the bistable devices and the vortex device being in series with the other bistable device. The monostable device has a plurality of control ports which are operative to bias the device towards its nonpreferred output passage and a pair of these control ports are communicated to the output passages of .its series connected bistable device. One of these communications includes a capacitive volume so that, as the output of the bistable device is switched between the output passages there will appear at the monostable device a momentary lapse of signal. The monostable device is arranged to provide the output signal for the time period that the lapse-in signal occurs. The vortex device is communicated through its outer wall port to the variable volume device so as to act as a variable restriction in controlling the rate of charging and discharging of the volume. The various engine responsive parameters are illustrated as being applied to and operative to control the various switching sequences of the first bistable device, the monostable device and the swirl rates and directions of the vortex device.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates a block diagram of a fluidic fuel injection system incorporating the present invention applied to a four-cylinder spark ignition internal combustion engine.

FIG. 2 illustrates a fluidic circuit diagram of the pulse generator according to the present invention and a pulse computer portion, the first and second stages of the injection controlling pulse former according to FIG. 1.

FIG. 3 illustrates a fluidic circuit for generating the primary engine speed pulse input for the pulse forming network of FIG. 2 and according to FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, the fluidic fuel injection system incorporating the present invention is illustrated in a block diagram form and associated with an internal combustion engine l. The engine 1 includes an intake manifold 2, having air cleaner-3 mounted thereon, and a plurality of fuel injectors 4 mounted on the manifold 2. The fuel injectors 4 are supplied from fuel reservoir or tank 5 with fuel which is pressurized by pump 6 and supplied through conduit means 7. Fuel pump 6 is illustrated as a constant delivery pump but other forms are well known. A pressure regulator 8 is illustrated in fluid communication with the conduit means 7 in order to provide a relatively uniform pressure at each of the injector valve means 4. An engine temperature snesor 9 is illustrated herein as associated with the engine 1 and is arranged to communicate a temperature signal to the temperature responsive fluidic circuitry as illustrated by the dashed lines. In addition, an engine speed sensor is illustrated as communicating with the engine pulley 10 to generate a speed signal and the manifold pressure sensor is illustrated as communicating with the intake manifold 2 to generate a signal indicative of the air pressure within the engine intake manifold 2.

The fluidic fuel injection system including the present invention is illustrated in FIG. 1 by the block diagram which is generally denoted as 12. The fluidic fuel injection system 12 is comprised of the fluidic monostable multivibrator circuit 14 according to the present invention which feeds fluidic pulses to the pulse computer 16 which in turn computes an injection pulse for application to the various injector valves 4. For the sake of example, the injector valves may be as illustrated in co-pending commonly assigned patent application Ser. No. 170,162 Gas Injection Liquid Flow Control Valve Clarence E. Vos or commonly assigned U.S. Pat. No. 3,665,949 entitled Gaseous Controlled Fluidic Throttling Valve issued to Jerome G. Rivard. In the embodiment illustrated, the pulse computer 16 applies the computed pulse to each of the injectors 4 simultaneously. This permits simultaneous injection of all injector valves 4. It would also be possible to provide a sequential injection system by selective AND gate coupling between one or more injectors 4 and the speed sensor 18. This would provide not only sequential injection in the event that the injectors 4 were individually coupled to the speed sensor through AND gate means, but could also be used to provide for group injection by combining two or more injectors and coupling them to the speed sensor for sequential injection of the various groups.

The monostable multivibrator 14 receives a plurality of inputs which are representative of the various operating conditions of the engine and are tailored to be representative of the preselected performance criteria for the internal combustion engine 1 to which the fuel system of the present invention is coupled. In the fuel system of the present invention, the primary inputs are by means of the speed sensor 18 and the manifold pressure sensor 20. The speed sensor 18 is coupled to ramp generator 22 which feeds an initiating input signal to input terminal 51 of the monostable multivibrator 14. The manifold pressure sensor receives a signal indicative of manifold pressure from the intake manifold 2 and applies this signal, suitably altered in accordance with the performance criteria previously mentioned, to the input terminal 55 of the monostable multivibrator 14. A signal is also communicated to the wide open throttle enrichment means 24 by the manifold pressure sensor 20 to provide a control fluid flow at input terminal'54 of the monostable multivibrator 14. Signals from the temperature sensor 9 are applied to the starting enrichment means 26 and the warm-up enrichment means 28. This temperature signal is operative to provide a selected form of fluid flow from the starting enrichment means 26 at the input terminal 59 of the monostable multivibrator l4 and it is also operative to provide for a selected warm-up enrichment fluid flow from the warm-up enrichment means 28 at input terminal 58 of the monostable multivibrator 14. Ramp generator means 22 also provides information signals for the information processing network 30 and the deceleration fuel cutoff network 32. The information processing network 30 provides a control signal indicative of engine speed and engine operational conditions to the flooding protection circuit 34 which, in turn, controls the fuel pump transducer 36. The fuel pump transducer merely operates to convert the fluid signal from the flooding protection circuit 34 into a suitable electrical or mechanical signal for application to the fuel pump 6. Information from the information processing network is also provided to the deceleration fuel cutoff cir cuit 32 to generate a control fluid flow at input terminal 53 of the monostable multivibrator 14. Speed sensor 18 also provides a signal for application to the rpm compensation circuit 38 which in turn provides a control fluid flow at the input terminal 52 of the monostable multivibrator 14. A preset threshold mechanism 40 provides a control signal for receipt by input terminal 57 of monostable multivibrator 14 to condition the response to monostable multivibrator 14 to the output of ramp generator 22 so as to correspond to a selected phase relationship between the engine speed sensor 18 and the initiation of the fuel injection controlling pulse by the pulse computer 16.

The system as hereinabove described operates as follows. Signals from the speed sensor 18 are applied to ramp generator 22 where they are converted to a ramp signal for application to the monostable multivibrator 14. A fluid signal having a predetermined level is also applied to monostable multivibrator 14 by the preset threshold means 40 and switching takes place when the ramp signal exceeds the preset threshold. The monostable multivibrator 14 will remain in its switched, or unstable, state for a period of time depending upon the signal received at input terminal 55 from the manifold pressure sensor 20. Further control signals may be appliedby the warm-up enrichment mechanism 28 and the rpm compensation means 38. In the event of a deceleration, the deceleration fuel cutoff means 32 will apply an inhibiting signal to prevent further pulse generation by the pulse generator means monostable multivibrator 14. In order to prevent engine flooding, the information processing unit 30 and the flooding protection circuit 34 may be arranged to respond to conditions which would otherwise generate engine flooding to modulate or terminate the output of the fuel pump 6. The output of the warm-up enrichment means 28 and the rpm compensation means 38 may be arranged to be fluid signals having a level indicative of the desired compensation or enrichment and may be combined with the signal from manifold pressure sensor 20 to affect the duration of the pulse produced by pulse generator means monostable multivibrator 14. The pulse generated by the pulse generator means monostable multivibrator 14 therefore has a duration which represents the quantity of fuel required by the engine for operation consistent with its predetermined operational requirements, This duration will not, however, necessarily be directly indicative of the requirement and to generate the injection command pulse which is directly indicative of the fuel requirement, computer 16 is arranged to receive the output signal from the monostable multivibrator l4, and also a signal from an engine parameter sensor such as, for instance, engine temperature sensor 9 to generate an output pulse which is directly indicative of the engine fuel requirement. By representative is meant that a pulse whose duration when multiplied by a factor which may be one but which may also be greater than one and which is determined by an engine operating parameter will yield the duration of fuel flow required by the engine to satisfy the predetermined operational characteristics of the engine. By indicative is meant a pulse whose duration is equal to the duration of fuel flow required by the engine.

Additionally, the present fluidic circuit includes a cold starting enrichment means 26 which also receives a temperature signal, in this instance from engine temperature sensor 9, and may also be arranged to receive a signal indicative that the engine is in the start mode to provide a fluid signal at monostable multivibrator 14 input terminal 59 to provide for the lengthening of the While the ramp generator 22 is operative to provide essentially a pulse having a monotonically increasing magnitude, the various other fluidic subcircuits which feed information into the enumerated input terminals of the monostable multivibrator circuit 14 are arranged to provide fluid signals having variable mangitudes which represent the operational conditions of the associated engine. In other words, ramp generator 22 provides a. digital input while the various other fluidic circuits provide analog inputs for the monostable multivibrator 14 which responds to these various inputs to provide an output pulse having a duration representative of the fuel injection quantity.

Referring now to FIG. 2, particular fluidic circuits will be described for the pulse generator means monostable multivibrator circuit 14 according to the present invention and for the pulse computer 16. It will be appreciated that the specific fluidic circuits and elements described hereinbelow are intended to be illustrative of the present invention and that various modifications and changes in the circuitry will be readily apparent. Departures from specific circuitry to achieve specific goals such as cost reduction use of commercially available elements and matching to specific fuel requirements are anticipated and their inclusion herein is intended. It should be noted that the specific fluidic circuits and elements described hereinbelow are described with reference to a system which utilizes a compressible fluid (for instance air) as the computational fluid and as a consequence, the various recited volumes, restrictions, and bleeds are shown with this computational fluid in mind. The man of ordinary skill in this art will readily recognize that other fluids and other forms of fluid impedance may be substituted. In addition, additional fluid impedances check valves and the like may be inserted as necessary to provide signal tailoring and flow direction control to suit particular requirements.

The pulse generator means monostable multivibrator 14 is comprised of first and second bistable fluidic amplifiers denoted as 141 and 142, monostable fluidic amplifier 143, and fluidic vortex device 144 having a vented output as illustrated. The fluidic amplifiers 141, 142, 143, are comprised of a source of power fluid denoted by the suffix letter a and also illustrated by a triangular fluid entry port, a pair of outlet passages denoted by the suffix letters b and c, and a plurality of control ports denoted by the suffix letters d through It, as appropriate. The output passages b and c of fluidic device 141 are communicated to control ports d and g of fluidic device 143. Control ports d and g are control ports arranged to one side of the fluidic device 143 and fluid flow therethrough is operative to bias fluid flow from the main nozzle, a, of device 143 to the output passage 0 of device 143 which, in this instance, is illustrated as being a nonpreferred fluid flow outlet passage. In the absence ofa biasing control fluid flow, fluid flow from the device 143 would be through the outlet passage, b, which is illustrated as being the preferred fluid flow outlet passage. As illustrated, passage, b, is indithrough geometry of the device, use of the Coanda effect in a selected outlet passage or through self-biasing fluid flow. The use of memory in this context is intended to mean any of the possible means of achieving a preferred fluid flow passage condition. Fluid flow in passage 0 of the device 143 is communicated back to the control ports e of devices 141 and 142, while fluid flow in passage b of device 143 is communicated to the pulse computer 16. A fluid volume, or fluid capacitance, is illustrated intermediate the outlet passage b of device 141 and the control nozzle g of device 143.

The output passages b and c of device 142 are arranged to provide for fluid swirl within vortex device 144 and are so arranged that fluid flow from passage b of device 142 would generate a clockwise fluid swirl within vortex device 144 while fluid flow from passage 0 of device 142 would generate counterclockwise swirl within vortex device 144. The restricted vents illustrated on the element 142 may be required for impedance matching with the vortex device 144. The outer wall outlet port or passage of vortex amplifier 144 is communicated to the fluid volume 145 intermediate the volume 145 and output passage b of fluid amplifier 141. As is known, the presence of swirl within a vortex device is operative to vary the ease with which fluid may flow through the outer wall port or passage of the device.

Input terminal 51 of monostable multivibrator 14 is communicated to control nozzles d of fluidic elements 141 and 142. Control nozzlefof fluidic element 141 is communicated to input terminal 53 of monostable multivibrator 14, control nozzle g of fluidic element 141 is communicated to input terminal 57 of monostable multivibrator 14, control nozzle e of fluidic element 143 is communicated to the input terminal 52 of the monostable multivibrator 14, control nozzle f is communicated to input terminal 56 of monostable multivibrator 14, control nozzle h is communicated to input terminals 54 and 55, in parallel, of the monostable multivibrator 14. For convenience, input terminals 52 and 56 and control nozzles e and f of device 141 are shown as being interconnected. Input terminals 58 and 59 are communicated to additional control nozzles associated with the vortex device 144. Intermediate input terminal 58 and the nozzle of vortex device 144 with which it is associated is situated a fluid restriction 146 and a fluid volume 147 which are operative to convert a pulse signal input received at input terminal 58 into a fluid level signal for application to the vortex device 144. Intermediate input terminal 59 and the control nozzle of vortex device 144 with which it is associated is situated a fluid restriction 148 a fluid volume 149 and a check valve 150 which may be required to prevent back flow from varible restrictor vortex device 144. The fluid restriction 148 and the fluid volume 149 are herein operative to convert a pulse signal received at the input terminal 59 to a fluid level signal for application to the vortex device 144.

The monostable multivibrator 14 as hereinabove described operates as follows. A fluid ramp signal is received at input terminal 51 and is communicated to the control nozzle d of each of the fluid amplifiers 141 and 142. Application of this signal to the control nozzle d of amplifier 142 is operative to cause main fluid flow from the main nozzle a to exit from the device through outlet passage b and to thereby generate a clockwise swirl within the vortex device 144. The application of the ramp signal to control nozzle d of the fluidic element 141 in conjunction with the threshold preset fluid level established at input terminal 57 will be operative to switch fluid flow from the main nozzle a to the output passage b when a predetermined (pressure) relationship exists between the instantaneous level of the ramp and the level of pressure received at input terminal 57. Fluid flow through outlet passage b of fluidic element 141 will be operative to charge the fluid volume 145 at a rate which is a function of the compressibility of the fluid in use and the size of the volume. Fluid flow through the outlet passage b of fluidic element 141 will occur only upon termination of fluid flow from outlet passage of element 141 and this will terminate the fluid pressure signal ordinarily received by control nozzle d of element 143. In the absence of a fluid signal at either of control nozzles d and g, fluid flow from the main nozzle a of element 143 will be through the preferred outlet passage b of element 143 and will appear as a pressure signal to the pulse computer. As fluid flow from outlet passage b of element 141 begins to charge the volume 145, the fluid pressure appearing at control nozzle 3 of element 143 will begin to increase. When the level of fluid signal appearing at control nozzle g of element 143 reaches a value which may be controlled by the value of the relatively high pressure signals re- 'ceived at input terminals 52 or 56, or relatively low pressure signals received at input terminals 54 and 55, the fluid flow from the main nozzle will be switched from outlet passage b to outlet passage 6 which is arranged in a feedback arrangement to provide a fluid pressure signal at the control nozzle e of the fluid elements 141 and 142. The presence of a fluid pressure signal in outlet passage c of element 143 will signal the termination of the pulse received by the pulse computer- 16 and will also cause the fluid elements 141 and 142 to switch so that fluid flow will appear in outlet passages c of each of elements 141 and 142. The presence of fluid flow in outlet passage 0 of element 141 will be operative to maintain the bias of fluid element 143 so as to maintain fluid flow through outlet passage 0. Additionally, the presence of fluid flow in outlet passage c of element 142 will oppose the clockwise swirl previously established in vortex device 144 by flow from passage b of element 142 and from input terminal 58 so that there will appear a state of no fluid swirl which may be followed by the generation of a weak counterclockwise fluid swirl should engine operating temperature not have been reached. During the time period where there is substantially no swirl within the vortex element 144, the fluid pressure previously accumulated in volume 145 will be rapidly vented into the vortex device and the volume 145 will be discharged. The appearance of the next ramp signal at input terminal 51 will reinitiate this process to generate an additional pulse for receipt by pulse computer 16. This next succeeding pulse will have a duration which is a function of the pressure signals received at the control nozzles e, f, and h of fluidic element 143, as well as the rate of charge of the fluid volume 145. The input terminals 58 and 59 are arranged to provide additional swirl inducing or inhibiting fluid flows at the vortex device 144 to modulate the swirl rate and to therefore provide a modulating fluid flow which may either add to or subtract from the fluid flow ordinarily entering the fluid volume during charging and pulse forming process.

The pulse computer 16 is comprised of a fluidic device 161 having a main fluid jet a, a pair of outlet passages b and c, and control nozzles d and e and a fluidic OR gate 165. Fluidic device 161 is arranged to receive at its control nozzle d the fluid pulse generated at outlet passage b of fluidic element 143 in the pulse computer 14. Receipt of this pulse is operative to bias fluid flow from the main fluid nozzle a of fluidic device 161 to outlet passage c, where it is communicated to control nozzle e of OR gate fluidic device through a bleed or fluid restriction 163. Intermediate the bleed 163 and the control nozzle e of fluidic device 165 is situated a fluid capacitance or volume 165.

The pulse from outlet passage b of fluidic device 143 of pulse computer 14 is also applied to one input of the OR gate 165, control nozzle d so as to provide an output signal which is substantially in phase with the pulse produced by the pulse generator 14. The pulse produced by pulse generator 14 is also operative to direct fluid flow through the outlet passage 0 of the fluidic element 161 to charge the volume 164. When the volume has reached a critical charge dependent upon fluid compressibility and volume, a pressure pulse will also appear at control nozzle e of fluidic device 165 and, in the presence of an output pulse from the pulse generator 14, would not alter or affect operation of the OR gate 165. However, upon termination of the pulse produced by pulse generator 14, fluid flow in the fluid device 161 would switch from the outlet passage c to the outlet passage b due to the monostable effect of the device discussed hereinabove and the charging of volume 164 would terminate. The accumulated charge in this volume would continue to apply a pressure pulse to the control nozzle e of the fluidic element OR gate 165 so as to cause it to generate an injection command pulse for a period of time following the termination of a pulse produced by pulse generator 14. Additionally, AND gate means 166 is illustrated as arranged to receive the pulse signal from pulse generator 14 as well as a signal from an engine operating condition sensor to generate an output signal for additionally effecting the charging of volume 164. AND gate 166 is of the-passive type and may be arranged to pass a signal whose magnitude is directly related to the magnitude of the signal received from the associated engine sensor during the receipt of a pulse from pulse generator 14 so as to provide a variable multiplicative factor in the relationship of the pulse computer output pulse and the pulse generator output pulse. In the herein illustrated embodiment, ANd gate 166 is arranged to receive a signal indicative of engine temperature through inlet conduit C.

Referring now to FIG. 3, the ramp generator 22 of FIG. 1 is illustrated in a fluidic circuit. The circuit is comprised of first and second fluid amplifying devices 221 and 222, a plurality of fluid bleeds or orifices 223, 224, 225, fluid volumes or capacitances 226, 227, and a fluid delay element 228. The fluidic devices 221, 222, are fluid proportional amplifiers having power nozzles a, outlet passages b and c and control nozzles d and e. The ramp generator is arranged to receive fluid pulses having a frequency which is indicative of the engine speed and is operative to apply these signals to various of the control nozzles of fluidic elements 221, 222. The fluid restrictive 224 and fluid capacitance 226 and the fluid restriction 225 and fluid capacitance 227 are operative to cause the pulse signal received from the speed sensor 18 to appear at the control nozzles e of the fluidic elements 221, 222 as a ramp signal, and the application of this signal to the control nozzle e of the fluidic amplifier 222 will be operative to cause a corresponding ramp signal to appear in the outlet passage b of that amplifier. Fluid restriction 223 on the other hand will be operative to convert a pulse from speed sensor 18 into a prolonged fluid pulse for receipt by control nozzle d of fluidic amplifier 221. The combination of the ramp signal at control nozzle e and the pulse signal at control nozzle d of amplifier 221 will be operative to cause the signal appearing in the outlet passage c of the fluidic amplifier 221 to be a relatively sharp pulse which rapidly drops off. This sharp pulse, which may be termed a spike" pulse, will appear at outlet passage A for use in fluidic circuitry as illustrated in FIG. 1 and will also be communicated to the control nozzle d of the fluidic amplifier 222 through the fluid delay means 228. This sharp signal upon receipt at control nozzle d of amplifier 222, will be operative to terminate the increasing ramp and therefore provide a sharp cutoff characteristic for the ramp signal. This signal will be communicated directly to the input terminal 51 of the pulse generator 14, as illustrated in FIG. 2.

I claim:

1. A fluidic monostable multivibrator circuit comprising in combination:

power fluid source means;

first bistable fluidic amplifier means having a main fluid nozzle, at least two opposed control nozzles, and a pair of outlet passage means;

triggering means coupled to one of said bistable means control nozzles operative to emit a fluid pulse train stream to direct main fluid flow to a first selected one of said pair of outlet passage means;

monostable fluidic element means having a main fluid nozzle, a plurality of control nozzles, a preferred outlet passage and a nonpreferred outlet passage, said plurality of control nozzles including two control nozzles adjacent said preferred outlet passage;

a pair of conduit means for communicating each of said bistable amplifier means pair of outlet passage means with differing ones of said two control nozzles adjacent the monostable element means preferred outlet passage and including means in one of said conduit means operative to delay in time the transmission of fluid pressure signals from one of said pair of bistable amplifier means outlet passages to its associated one of the two monostable element means control nozzles;

feedback conduit means intercommunicating said monostable element means nonpreferred outlet passage with the other of said bistable means control nozzles whereby fluid flow in said monostable element means nonpreferred outlet passage will cause fluid flow from said bistable amplifier means to be in a selected one of said pair of bistable amplifier means outlet passages which is not the first selected one of said pair of outlet passages; and

control means communicating with said one conduit means intermediate said bistable amplifier means and said delay means operative to modulate the transmission of fluid pressure signals to the delay means thereby effectively varying the time delay of signal pressure transmissions imposed by said delay means and to generate an output pulse in said monostable element means preferred outlet passage in one-to-one relationship with the pulses of said triggering means fluid pulse train.

2. The circuit as claimed in claim 1 wherein said feedback conduit means communicate with said bistableamplifier means control nozzle ajdacent the first selected one of said pair of bistable amplifier means outlet passage means. i

3. The circuit as claimed in claim 1 wherein said control means comprise:

vortex valve means having inlets and an exhaust passage which is communicating with said feedback conduit means; and

controllable means coupled to the vortex valve means inlets operative to establish a controllable fluid swirl in said vortex valve.

4. The circuit as claimed in claim 3 wherein said controllable means comprise:

second bistable amplifier means having a main fluid nozzle, a pair of opposed control ports and a pair of outlet passage means;

first conduit means communicating one of said pair of outlet passage means to the inlet means of said vortex valve means; and

fluid flow means connected to said pair of control nozzles operative to control fluid flow through said pair of outlet passage means.

5. The circuit as claimed in claim 4 wherein said fluid flow means comprise:

first fluid conduit means intercommunicating one of said second bistable amplifier means control nozzles with said feedback conduit means; and second fluid conduit means intercommunicating the other of said second bistable amplifier means control nozzles with said triggering means.

6. The circuit as claimed in claim 5 including further flow additive means connected to said vortex valve inlet means operative to add fluid swirl in said vortex valve.

7. The circuit as claimed in claim 5 including further flow subtractive means connected to said vortex valve inlet means operative to reduce fluid swirl in said vortex valve.

8. The circuit as claimed in claim 4 including second conduit means communicating the other of said pair of outlet passage means to the inlet means of said vortex valve means, said first and second conduit means and associated inlet means arranged to provide oppositely directly fluid swirl within said vortex valve.

9. A fluidic monostable multivibrator circuit comprising:

a monostable fluidic element having a power nozzle,

a pair of outlet passages comprising a preferred outlet passage and a nonpreferred outlet passage and a plurality of control nozzles disposed adjacent said preferred outlet passage;

means for providing a main fluid flow through said element;

capacitive means including a fillable volume in fluid communication with said one of said control nozzles, said capacitive means adapted to receive a pulse train signal having a substantially constant pulse magnitude and to transmit a fluid pulse train signal comprised of pulses having a magnitude that increases with elapsed time from the time of initiation of the transmitted pulse;

vortex valve means having exit passage means communicating with said volume, said valve means having means for establishing a vortex swirl and means for modulating said vortex swirl to vary the degree of fluid flow through said exit passage means thereby controlling the rate at which said volume is filled or emptied; and

first variable level signal generating means for applying a variable signal to a second one of said control nozzles, said pulse train signal and said variable level signal cooperative to cause fluid flow through said fluidic element to switch from the preferred outlet to the nonpreferred outlet at a predeterminable time relative to the time of initiation of the pulse.

10. The circuit as claimed in claim 9 wherein said fluidic element includes at least one control nozzle disposed adjacent said nonpreferred outlet passage and arranged to discharge a control pressure fluid flow generally opposed to the variable signal.

11. The circuit as claimed in claim 10 including second variable level signal generating means for applying a variable signal to said at least one control nozzle.

12. The circuit as claimed in claim 11 wherein said fluidic element control nozzle and outlet passages are arranged so that a predetermined minimum of control nozzle fluid flow is required to effect switching of said main fluid flow from said preferred outlet passage to said nonpreferred outlet passage. 

1. A fluidic monostable multivibrator circuit comprising in combination: power fluid source means; first bistable fluidic amplifier means having a main fluid nozzle, at least two opposed control nozzles, and a pair of outlet passage means; triggering means coupled to one of said bistable means control nozzles operative to emit a fluid pulse train stream to direct main fluid flow to a first selected one of said pair of outlet passage means; monostable fluidic element means having a main fluid nozzle, a plurality of control nozzles, a preferred outlet passage and a nonpreferred outlet passage, said plurality of control nozzles including two control nozzles adjacent said preferred outlet passage; a pair of conduit means for communicating each of said bistable Amplifier means pair of outlet passage means with differing ones of said two control nozzles adjacent the monostable element means preferred outlet passage and including means in one of said conduit means operative to delay in time the transmission of fluid pressure signals from one of said pair of bistable amplifier means outlet passages to its associated one of the two monostable element means control nozzles; feedback conduit means intercommunicating said monostable element means nonpreferred outlet passage with the other of said bistable means control nozzles whereby fluid flow in said monostable element means nonpreferred outlet passage will cause fluid flow from said bistable amplifier means to be in a selected one of said pair of bistable amplifier means outlet passages which is not the first selected one of said pair of outlet passages; and control means communicating with said one conduit means intermediate said bistable amplifier means and said delay means operative to modulate the transmission of fluid pressure signals to the delay means thereby effectively varying the time delay of signal pressure transmissions imposed by said delay means and to generate an output pulse in said monostable element means preferred outlet passage in one-to-one relationship with the pulses of said triggering means fluid pulse train.
 2. The circuit as claimed in claim 1 wherein said feedback conduit means communicate with said bistable amplifier means control nozzle ajdacent the first selected one of said pair of bistable amplifier means outlet passage means.
 3. The circuit as claimed in claim 1 wherein said control means comprise: vortex valve means having inlets and an exhaust passage which is communicating with said feedback conduit means; and controllable means coupled to the vortex valve means inlets operative to establish a controllable fluid swirl in said vortex valve.
 4. The circuit as claimed in claim 3 wherein said controllable means comprise: second bistable amplifier means having a main fluid nozzle, a pair of opposed control ports and a pair of outlet passage means; first conduit means communicating one of said pair of outlet passage means to the inlet means of said vortex valve means; and fluid flow means connected to said pair of control nozzles operative to control fluid flow through said pair of outlet passage means.
 5. The circuit as claimed in claim 4 wherein said fluid flow means comprise: first fluid conduit means intercommunicating one of said second bistable amplifier means control nozzles with said feedback conduit means; and second fluid conduit means intercommunicating the other of said second bistable amplifier means control nozzles with said triggering means.
 6. The circuit as claimed in claim 5 including further flow additive means connected to said vortex valve inlet means operative to add fluid swirl in said vortex valve.
 7. The circuit as claimed in claim 5 including further flow subtractive means connected to said vortex valve inlet means operative to reduce fluid swirl in said vortex valve.
 8. The circuit as claimed in claim 4 including second conduit means communicating the other of said pair of outlet passage means to the inlet means of said vortex valve means, said first and second conduit means and associated inlet means arranged to provide oppositely directly fluid swirl within said vortex valve.
 9. A fluidic monostable multivibrator circuit comprising: a monostable fluidic element having a power nozzle, a pair of outlet passages comprising a preferred outlet passage and a nonpreferred outlet passage and a plurality of control nozzles disposed adjacent said preferred outlet passage; means for providing a main fluid flow through said element; capacitive means including a fillable volume in fluid communication with said one of said control nozzles, said capacitive means adapted to receive a pulse train signal having a substantially constant pulse magnitude and to trAnsmit a fluid pulse train signal comprised of pulses having a magnitude that increases with elapsed time from the time of initiation of the transmitted pulse; vortex valve means having exit passage means communicating with said volume, said valve means having means for establishing a vortex swirl and means for modulating said vortex swirl to vary the degree of fluid flow through said exit passage means thereby controlling the rate at which said volume is filled or emptied; and first variable level signal generating means for applying a variable signal to a second one of said control nozzles, said pulse train signal and said variable level signal cooperative to cause fluid flow through said fluidic element to switch from the preferred outlet to the nonpreferred outlet at a predeterminable time relative to the time of initiation of the pulse.
 10. The circuit as claimed in claim 9 wherein said fluidic element includes at least one control nozzle disposed adjacent said nonpreferred outlet passage and arranged to discharge a control pressure fluid flow generally opposed to the variable signal.
 11. The circuit as claimed in claim 10 including second variable level signal generating means for applying a variable signal to said at least one control nozzle.
 12. The circuit as claimed in claim 11 wherein said fluidic element control nozzle and outlet passages are arranged so that a predetermined minimum of control nozzle fluid flow is required to effect switching of said main fluid flow from said preferred outlet passage to said nonpreferred outlet passage. 